It’s often been noted that before the civil rights era, the American South, while more racist than the North, was in one way more enlightened: Even at the vicious height of Jim Crow, blacks and whites coexisted with a casual and enduring day-to-day intimacy. They’d been living intertwined lives, after all, since the days of slavery. The Help, an emotionally enveloping, sharply alive big-canvas adaptation of Kathryn Stockett’s powerful 2009 novel, is rooted in that truth more deeply than just about any Hollywood movie I can name. It understands that the ”separation” of the races in the South wasn’t just a crime — it was a grand illusion.

Early on, Aibileen Clark (Viola Davis), grave and solid, with a look so impassive it takes you a moment to see the silent protest in her eyes, tells us that she’s a maid just like her mother, and that her grandmother was a house slave. It’s 1961, and the matter-of-fact way that she delivers that information is startling, because she’s really telling us that she’s a house slave too. She’s just called by a different title. She also says that she has raised 17 white children, so that’s another way that the word maid seems inadequate. She’s a nanny — and in many ways, a surrogate mother.

Set in Jackson, Miss. — the middle-class heart of the Deep South — The Help is Aibileen’s story, and it’s also the story of her best friend, Minny (Octavia Spencer), a pixie-faced rascal of a housekeeper/cook who’s as feisty and contemptuous as Aibileen is circumspect. Davis and Spencer are both brilliant, etching these women’s hopes and broken dreams with every line, and between the lines, too. The film is also about their comrades, and about the women they work for — a group of eager, perky housewives (they’re like Southern-fried Betty Drapers) who are just the sort of bridge-club-and-benefit types that the movies love to caricature.

Yet one of the scrupulous pleasures of The Help is that there isn’t a caricature in it. Every woman on screen is fresh, live, and three-dimensional, whether it’s Elizabeth (Ahna O’Reilly), the girlish conformist who cedes her motherly duties, including nurturing, to Aibileen; Hilly (Bryce Dallas Howard), the snarling princess and out-of-the-closet racist who thinks that by forcing Minny to use a bathroom out back, she’s preserving the cause of racial harmony (she’s keeping everything in its place); or Celia (Jessica Chastain), the flaky, lost, Marilyn-esque white-trash rich girl who hires Minny on the sly. In The Help, the issue of the bathroom becomes nearly mythic — the domestic equivalent of lunch counters and the back of the bus. Bryce Dallas Howard, playing the soul of what had to be changed, gives a fearless performance, her smile treacherous, her eyes awake to every nuance of subservience (from her maid, and her friends, too).

Hilly’s old cohort, just returned from college, is Skeeter Phelan (Emma Stone), who has already outgrown this circle but isn’t quite sure where to turn. She takes a job at the Jackson Journal, doing a cleaning-advice column, and since she knows nothing about housework, she decides to get notes from Aibileen. That, in part, is what spurs Skeeter to do a book of interviews with the maids of Jackson, telling the story of Southern domestic life from their point of view. The book is dangerous to write, and ends up causing quite a stir, and that’s the film’s main motor. I’ve loved Stone as a wide-eyed comic sprite, but here, playing a young woman more no-nonsense than anyone around her, she doesn’t just sparkle — she holds the movie together. Pestering her mother (Allison Janney) to tell her why Constantine, the family maid of 29 years, was mysteriously let go, she makes you feel everything that maid meant to her. And Cicely Tyson, in flashbacks, makes Constantine, with her speech impediment, so vulnerable yet squinchy-eloquent that your heart breaks for her.

The Help has a saucy, humorous side. The film turns on a hilariously vengeful incident in which Minny delivers a very just dessert to Hilly. After a while, though, the humiliation wrung out of that moment becomes overkill. The Help was written and directed by Tate Taylor, who is not a film artist (I kept trying to imagine what Robert Altman might have done with this ensemble), yet he keeps hitting full, sturdy notes of straight-down-the-middle emotion. The movie isn’t perfect; it sometimes shows its stitching. But mostly it’s a stirring salute to subjugated women who hold their heads high. A-